This invention relates to a device for driving lengthwise continuous thin wall tubing, to a tube straightening mechanism and to a tube length control mechanism, as well as to a device for driving continuous thin wall tubing through a tube straightening device, to and through a tube cutting device, which tube cutting device is activated by a tube length control which monitors the length of tubing to be cut and activates the tube cutting device only when the precise tube length is presented thereto.
This invention arose out of a need to supply tubing cut to specific lengths requested by customers. Over the years, demand for precise lengths in cut tubing has risen and customers have certain needs which require tubing of precise length for use in its equipment and installations. In the past, maintaining precise length in cutting a plurality of tubes to length has been difficult and certain customers have been noted for returning whole lots of cut tubing if one tube in the lot is detected as being out of compliance with the customer""s request, the thought being that if one tube is not cut to the requested length there must be multiple tubes also not cut to the requested length. Further, the customer does not want to have to spend its time sorting the tubing to find those that are not of the requested length.
In addition to the necessity of accurately controlling tube length, there is the desire to make the cut tube lengths straight. Tube straightening mechanisms are known but all seemingly suffer from the serious disadvantage that much time and tubing is required to effect an accurate adjustment of the next set of tube engaging rollers to accommodate a different size tubing.
Therefore, it is an object of this invention to provide a system for repetitively cutting continuous length tubing to specific lengths and without the need for human intervention for the purpose of monitoring the cut tubing to make certain that the tubing complies with the customer""s request.
It is a further object of the invention to provide a system, as aforesaid, wherein the tubing to be cut is first drawn through a tube straightening device by a conveyor belt tube driving mechanism, the straightened tube being frictionally engaged by opposing surfaces of the conveyor belt system to frictionally drive the tubing lengthwise thereof.
It is a further object of the invention to provide a tube length control for controlling activation of an intermittently driven drive motor for a tube driving mechanism during a dwell period for the drive motor to precisely orient a length of tubing to be cut relative to a tube cutting device and only when the precise location has been determined by the tube length control is the tube cutting device activated to effect a severing of the tube from the continuous length tube supply.
It is a further object of the invention to provide a tube straightening mechanism which is quickly and easily adjustable to accommodate different diameter tubing thereby substantially reducing the magnitude of the down time for the changeover to different diameter tubing.
It is a further object of the invention to provide a tube straightening mechanism, as aforesaid, wherein plural pairs of a first set of tube engaging rollers each having tube guiding grooves therein are replaceable with a second set of preadjusted rollers with different size tube guiding grooves therein and into the same support as is used for the first set of tube engaging rollers.
The objects and purposes of the invention are met by providing a supply of continuous thin wall tubing which is drawn by a pair of opposed conveyor belts frictionally engaging the outside surfaces of the tubing first through a tube straightening device before the tube walls become engaged by the aforesaid conveyor belts so that straightened tubing is always subjected to engagement with the surfaces on the conveyor belts. The conveyor belts effect a longitudinal driving movement of the continuous tubing through the tube straightening mechanism and into and through a tube cutting device and thence into a tube length control for accurately positioning the tubing relative to the tube cutting device and before the tube is cut. Once the tube length detection circuitry has been satisfied by the positioning of the tubing, the tube cutting device is activated to sever the tubing.
The objects and purposes of the invention are also met by providing a tube straightening mechanism which has interchangeable, preadjusted sets of tube working rollers for quickly facilitating a change over to different size tubing and without wastage of tubing.